Model Descriptions & Conventions?

M2.SO. The third letter references the blade finish whereas the fourth letter describes the scale color (black/coyote/olive). There are several letters referencing the finish including A/B/F/S. B is Black and F seems to be Flat Dark Earth. Is S for Stainless Steel (Gray)? What type of finish does A refer to? Anthracite (Black)?

Everything that precedes the "." is the model of the blade. In this case, M2. Everything following the "." denotes the colors for the blade and handles. First letter is DLC coating color, second and subsequent letters denote handle color. Blade colors are B=black, F=FDE, A=anthracite grey, S=silver grey. Standard handle colors are B=black, C=coyote, O=OD. So in the case of the example you cited, SO would be sliver grey DLC with OD handles.